Table 1.
Characteristics of imaging techniques for hepatic steatosis evaluation
|
Techniques
|
Clinical characteristics
|
Limitations
|
| CAP | Low cost; High availability; Time-saving | High measurement failure rate |
| Allows simultaneous evaluation of steatosis and fibrosis | Measurement without B-mode ultrasound image | |
| Moderate to high diagnostic accuracy for detecting and grading steatosis | The cutoff value for diagnosing steatosis is poorly standardized | |
| Moderate to high repeatability and reproducibility | ||
| Well validated | ||
| ATI, ATT and UGAP | Outperform or have comparable diagnostic accuracy compared with CAP | The measurement may be influenced by liver fibrosis |
| High repeatability and reproducibility | Fairly small number of studies | |
| Strong correlation with liver histology or MRI-PDFF | ||
| Low measurement failure rate | ||
| Measured on B-mode ultrasound images | ||
| Att. PLUS | Measurement is obtained at the same time as the sound speed measurement | Fairly small number of studies |
| Comparable diagnostic accuracy with CAP | No study comparing this technique with liver histology or MRI-PDFF | |
| TAI and TSI | High diagnostic accuracy for detecting and grading steatosis | Fairly small number of studies |
| Strong correlation with MRI-PDFF | ||
| High repeatability and reproducibility | ||
| BSC | Uses a reference phantom to reduce sources of variability due to ultrasound systems or operators | Fairly small number of studies |
| High diagnostic accuracy for detecting and grading steatosis | ||
| Strong correlation with liver histology or MRI-PDFF | ||
| High repeatability and reproducibility | ||
| UDFF | Is a combination of both attenuation coefficient and backscatter coefficient | Fairly small number of studies |
| UDFF approximates MRI-PDFF | ||
| ASQ and NLV | Moderate to high diagnostic accuracy for detecting and grading steatosis | Weak correlation with liver histology |
| Strong correlation with CAP | The correlation with MR-based techniques is controversial | |
| The influence of fibrosis on measurement is controversial | ||
| Fairly small number of studies | ||
| SS | Moderate to high diagnostic accuracy for detecting and grading steatosis | Fairly small number of studies |
| Strong correlation with CAP | ||
| MRS and MRI-PDFF | High diagnostic accuracy for detecting and grading steatosis | High cost; low availability |
| Considered as the reference standard | Time-consuming |
CAP: Controlled attenuation parameter; ATI: Attenuation imaging; ATT: Attenuation measurement function; UGAP: Ultrasound-guided attenuation parameter; Att. PLUS: Attenuation plane-wave ultrasound; TAI: Tissue attenuation imaging; TSI: Tissue scatter distribution imaging; BSC: Backscatter coefficient; UDFF: Ultrasound-derived fat fraction; ASQ: Acoustic structure quantification; NLV: Normalized local variance; SS: Speed of sound; MRS: Magnetic resonance spectroscopy; MRI-PDFF: Magnetic resonance imaging-proton density fat fraction.